Åkerman, Jonas

KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.

2011 (English)Doctoral thesis, comprehensive summary (Other academic)

Abstract [en]

Future transport systems consistent with long-term climate targets are examined in this thesis, using a systems perspective covering the entire transport system. Aviation is given particular attention, as expansion of this mode is difficult to reconcile with climate targets. The aim is to provide scientific decision support for current transport policy-making, especi-ally regarding structures with high inertia, e.g. urban structure, roads, railways, fuel produc-tion systems and vehicle fleets. An additional aim is to widen the perception of possible transport futures consistent with meeting climate targets, and to support a wider discussion in society on this topic. Papers I and III are backcasting studies which encompass the whole transport system. Paper III outlines an image of future Swedish transport by 2050, in which energy use per capita is reduced by 60%. This reduction is consistent with a 42% reduction in total global greenhouse gas emissions. Paper IV shows that total air travel by Swedes generates about 8.7 million tons of CO2-equivalents annually. This corresponds to about 12% of total Swedish emissions. Considering the rapid growth in emissions, aviation is key to achieving overall climate targets. Paper V indicates that building high-speed tracks between Stockholm, Gothenburg and Malmö may yield emissions reductions of about 550,000 tons of CO2-equivalents annually, if a life-cycle perspective is considered for all modes. However, this reduction is contingent on continuing growth of transport volumes, which seems diffi-cult to reconcile with the images in Papers II and III. This might consequently be a „second best‟ solution if a more radical break in transport growth is deemed unlikely due to external drivers.

The overall conclusion from this thesis is that improved vehicle technology and low carbon fuels are necessary, but not solely sufficient, to achieve long-term targets consistent with limiting global warming to two degrees. The growth in volume, especially of car and air travel and truck transport, must also be curbed. However, total travel volume can be maintained at 2005 levels if substantial modal shifts to cycling and public transport are achieved. Moreover, if conscious measures are taken regarding urban planning and the use of communications technology to replace travel, functional accessibility may increase considerably. The trend-breaking development needed to achieve climate targets requires a combination of different policy measures. Pricing of external effects, e.g. greenhouse gas emissions, is a key strategy and would involve ending aviation‟s exemption from carbon tax and value-added tax. Other possible pricing measures include differentiated charges for car travel in urban areas, km-charges on trucks and increased fuel taxes. However, to gain acceptance for pricing measures and maintain a well-functioning society, better alternatives with a lower climate impact are needed. Increased road capacity in urban areas usually increases car travel. Therefore, to achieve the targets set, strict prioritisation of investments in public transport, cycling and ICT infrastructure is needed, especially since public resources are limited. Another conclusion is that, for transport policies to be effective and not lead to sub-optimisations, it is necessary to consider the wider system delimitations explored in this thesis.

Abstract [en]

It is essential to take a longer term view if sustainable mobility is to become a reality. This paper takes a perspective to 2020 and constructs Images of the future which conform to the principles of sustainable mobility. Set at the EU level, clear environmental, regional development and efficiency targets are set, within which strategies are developed, based on different combinations of technological innovation and the decoupling of economic growth from transport growth. The external political situation is taken as given with either a move towards greater co-operation (and extension) or towards greater fragmentation (and regionalisaization) in Europe. The three Images of the future (2020) demonstrate that challenging targets for sustainable mobility can be achieved through a range of different policy actions within the transport sector and more widely. Immediate action is required and even more difficult choices will have to be made in the EU 15, if large-scale extension of the EU takes place. Improvements in vehicle technology alone will not achieve the targets. More fundamental changes have to take place in the way in which people make travel choices and in the means by which freight is transported. All of these measures must involve less travel, more efficient and cleaner travel modes.

Abstract [en]

In this paper three 'Images' of air travel on a sustainable path in 2050 are outlined. The method used is backcasting. A stabilization of the carbon dioxide concentration in the atmosphere at 450 parts per million is assumed to constitute a sustainable level. It is concluded that a refinement of the conventional turbofan aircraft is probably not sufficient to reach even the less demanding target level, even though a 40% reduction of fuel intensity may be achieved. The introduction of more radical aircraft configurations, e.g. the flying wing, probably has the greatest potential for reducing fuel consumption, but the development of such aircraft is uncertain. A less risky strategy is to opt for a high-speed propeller aircraft with a cruise speed which is 20-25% lower than for a conventional turbofan aircraft. This configuration entails a 56% cut of carbon dioxide emissions per passenger-kilometre compared to 2000. If this technology trajectory is combined with a development characterized by a weakened emphasis on economic growth together with less hectic lifestyles, it may be possible to reach even the most demanding of the target levels. Air travel per capita in 2050 would then be slightly higher than in 2000. If only the less demanding target level is to be reached global air travel per capita may be about 110% higher than in 2000.

Åkerman, Jonas

KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.

Höjer, Mattias

KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies. School of Computer Science and Communication (CSC), Centres, KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Sustainable Communications, CESC.

Abstract [en]

In this paper an image of a sustainable transport system for Sweden in 2050 is outlined. The emissions per capita in this image may be generalized to a global population of 9 billions, and still be consistent with a stabilization of the carbon dioxide concentration at 450ppm (parts per million). Swedish transport energy use per capita is 4.6MWh in the image, compared to 12.5MWh at present. The aim is, first, to widen the perspective of sustainable transport futures and, second, to provide a basis for present decisions in areas characterized by a high inertia, e.g. regarding infrastructure and the built-up environment. All transport generated by the lifestyles of Swedish residents are included. The reduction of energy use in the image is primarily achieved by an introduction of energy efficient vehicles and a conscious combination of IT-services and urban planning. The latter aims at increasing functional accessibility while reducing commuting. A prioritization of leisure travel to structurally-enforced travel gives the possibility to increase leisure travel per capita by one third. However, this is contingent on a 50% reduction of per capita car travel in cities. Given the set-up target, it may be concluded that the need for new arterial road capacity in cities often is negligible, even with a considerable population increase.

Abstract [en]

International travel is increasing rapidly, but emissions from this segment are not included in the Kyoto Protocol and seldom in national statistics. The aim of this paper is to estimate the volume of international travel by the Swedish population, and the emissions of greenhouse gas associated with that travel. Data used are from a national travel survey for 2006 including 27,000 telephone interviews. It is shown that international travel by the Swedish population amounted to 37 billion passenger-km, or 4100 km per capita in 2006. This corresponds to 22.5% of total travel by Swedes, an increase from 16.6% in 1994. Emissions of greenhouse gases from international travel by the Swedish population in 2006 amounted to 8.5 million tons of carbon dioxide equivalents, of which 92% stems from air travel. This is approx. 11% of total Swedish emissions including international transport. It is concluded that a continued growth of international travel at current pace hardly may be reconciled with long-term climate targets.

Abstract [en]

In this paper a life cycle perspective is used to analyse Europabanan, a proposed high-speed rail track in Sweden. The life cycle emissions reductions are found to be 550,000 tons of CO2-equivalents per annum by 2025/2030 with almost 60% of this coming from a shift from truck to rail freight and 40% from a shift from air and road travel to high-speed rail travel. In contexts similar to Sweden, it is thus an important issue whether a large increase is required in freight rail capacity anyway, since high-speed rail investments may not be justified for the passenger markets alone. The study also indicates that a substantial share of emissions due to construction of the new railway could be counterbalanced through the reduced need for building and maintaining roads and airports, and for manufacturing cars.